JPS6354557A - Air conditioner - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heat pump type air conditioner, and in particular to controlling the opening and closing of an electric expansion valve according to the operating state of the air conditioning system. Regarding the harmonizer.

[Conventional technology]

FIG. 9 is a basic configuration diagram showing a refrigeration cycle of a heat pump air conditioner disclosed in, for example, Japanese Utility Model Application Publication No. 59-23065.

In the same figure, ■ is a compressor, 2 is a four-way valve connected to the discharge side of the compressor 1, 3 is an electric expansion valve 54 is an indoor heat exchanger, 5 is an outdoor heat exchanger □ 6 is the compressor Machine 1. Four-way valve 2. This is a control unit that controls the electric expansion valve 3 and the fans 4a and 5a of the indoor and outdoor heat exchangers 4 and 5. Detection signals are inputted from the detectors 6a, 6b and the temperature detectors 6c, 6d which detect the temperatures of the indoor and external heat exchangers 4.5.

FIG. 10 shows a specific circuit diagram of the control section 6. As shown in FIG. This control unit 6 is composed of a microcomputer, and includes a central processing unit (hereinafter abbreviated as CPU) 7, and a memory 8 that stores data such as the operation control program of the air conditioner and the arithmetic processing results of the CPU 7. , an input circuit 9 and an output circuit 10. Further, a detection section 11 for detecting the operating state of the freezing cycle is connected to the input circuit 9, and this detection section 11 is connected to the temperature detectors 6a to 6a in FIG.
This corresponds to 6d. 12 is a drive circuit connected to the output circuit 10, which connects the compressor motor 1a, the electric expansion valve 3, and the fan motors 4b, 5 of the indoor/outdoor heat exchanger 4.5.
b.

Such a control unit 6 calculates operating conditions of the compressor motor la, electric expansion valve 3, and fan motors 4b and 5b from the temperature information detected by the detection unit 11 according to a control program stored in the memory 8. Based on this, the compressor 1 is controlled to start and stop so that the indoor temperature reaches a predetermined set temperature, and an electric motor is operated to prevent the refrigerant liquid from returning to the compressor 1 and maintain the maximum capacity. The expansion valve 3 will be controlled to open and close.

FIG. 11 shows a functional block diagram for controlling the opening and closing of the electrically operated expansion valve 3, in which the electrically operated expansion valve An opening degree determining means 13 for determining whether the opening degree of the expansion valve 3 is close to opening or close to closing, and a correction opening determining means for determining a correction value for the current opening degree of the electric expansion valve 3 from the determination result of this determining means 13. degree determining means 14; and an opening degree controlling means 1 for controlling the opening degree of the electric expansion valve 3 based on the result of the determining means 14.
5.

Next, the operation of the conventional heat pump type air conditioner configured as described above during heating operation will be explained according to the flowchart shown in FIG. 12.

When an operation switch (not shown) is turned on, the control section 6 starts operating, and the program shown in FIG. 12 starts. Accordingly, first, in step 20, the discharge refrigerant temperature of the compressor 1 and the suction refrigerant temperature of the compressor detected by the temperature detectors 6a and 6b are taken in. Then, in the next step 21, the compressor discharge refrigerant temperature 'FOU? and the minimum value T0 of the set temperature range are compared, and step 22.
As shown in 24, an opening/closing command is output from the control unit 6 to the electric expansion valve 3 via the drive circuit 12. That is, in step 23, if the compressor discharge refrigerant temperature T 0tl t is higher than the minimum value T0 of the set temperature range, the process proceeds to step 24, where the electric expansion valve 3 is opened and the compressor discharge refrigerant temperature T is increased. U, is the minimum value T of the set temperature range. If it is lower, the process proceeds to step 22 and the opening degree of the electric expansion valve 3 is closed.

Next, in step 23, the compressor discharge refrigerant temperature TOLIT
and the maximum value T1 of the set temperature range, and based on the comparison result, the electric expansion valve 3 as shown in step 22.24 is
Opening/closing commands are output. That is, in step 23, if the compressor discharge refrigerant temperature TOUT is higher than the maximum value T of the set temperature range, the process moves to step 24, where the opening degree of the electric expansion valve 3 is opened, and the compressor discharge refrigerant temperature T out becomes the set temperature. If it is lower than the maximum value T in the range, the process returns to step 22 and the opening degree of the electric expansion valve 3 is closed.

Next, in step 25, the compressor suction refrigerant temperature TIN and the set temperature T2 are compared, and according to the comparison result, an opening/closing command for the electric expansion valve 3 as shown in steps 24 and 26 is output. That is, in step 25, if the compressor suction refrigerant temperature T1N is higher than the set temperature T2, the process proceeds to step 24 and opens the electric expansion valve 3, and if the compressor suction refrigerant temperature Til+ is lower than the set temperature T2, Proceeding to step 26, the opening degree of the electric expansion valve 3 is closed.

Therefore, by adjusting the opening degree of the electric expansion valve 3, the air conditioner can maintain an optimal state depending on the operating state.

[Problem that the invention seeks to solve]

As mentioned above, conventional air conditioners control the opening and closing of the electric expansion valve based only on the discharge refrigerant temperature and suction refrigerant temperature of the compressor, so the electric expansion valve may not operate due to a malfunction or other reason. For example, if the electric expansion valve does not operate with its opening fully closed, the air conditioner will not operate even though the control unit is commanding the opening signal for the electric expansion valve. The state is such that the operation continues. As a result, not only the capacity of the components of the refrigeration cycle cannot be achieved, but also the refrigerant does not circulate to the compressor, which can cause serious malfunctions such as winding burnout due to temperature rise in the windings of the compressor motor. There was a problem.

This invention was made to solve the above-mentioned problems, and even if the electric expansion valve fails, it is possible to prevent serious accidents such as damage to the compressor from occurring. The purpose is to provide a harmonizing machine.

(Means for Solving the Problems) The air conditioner according to the present invention has a control unit that controls the start/stop of the compressor and the opening/closing of the electric expansion valve according to temperature information, and includes a control unit that counts the time from the start of the compressor. a time setting means for setting a time, a means for determining an abnormality of the electric expansion valve based on the heat exchanger temperature or room temperature at the time of starting the compressor and after the elapse of the time set by the time setting means; A means is added to stop the operation of the VA machine when an abnormality in the valve is detected.

[For production]

In this invention, the abnormality determination means for the electric expansion valve includes:
If it is determined that the difference between the heat exchanger temperature when the compressor is started and the heat exchanger temperature after a certain period of time or the difference between the indoor temperature after a certain period of time is below the set value, all electric expansion valves are It is determined that an abnormality due to the closed fixation has occurred, and as a result, the compressor stop control means is operated to stop the compressor, that is, the air conditioner. Therefore, even if the electric expansion valve remains fully closed and fixed, it is possible to prevent the compressor from overheating and burning out.

〔Example〕

Embodiments of the air conditioner of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a control system showing a first embodiment of an air conditioner according to the present invention.

In the figure, a control unit 30 composed of a microcomputer includes a CPU 31, a memory 32 that stores data such as an operation control program for the air conditioner and arithmetic processing results at the CPIJ 30, and an input circuit 33 connected to the CPU 30. and an output circuit 34. Above input circuit 3
3 receives temperature information from the temperature detection section 11 corresponding to the temperature detectors 6a to 6c as in the past, and the output circuit 34 receives the temperature information from the compressor motor l.
A, a drive circuit 12 that drives the electric expansion valve 3 and fan motors 4b and 5b for indoor and external heat exchangers is connected.

The control unit 30 configured in this manner controls the compressor motor la, the electric expansion valve 3, and the fan motor 4b based on the temperature information detected by the temperature detection unit 11.

5b is calculated according to the control program stored in the memory 32, and based on this, the compressor is controlled to start and stop so that the indoor temperature reaches the set temperature, and the refrigerant liquid is prevented from returning to the compressor, The opening and closing of the electric expansion valve 3 will be controlled so that the maximum capacity can be maintained.

FIG. 2 shows a functional block diagram of an opening/closing control section for the electric expansion valve 3 and an abnormality determination section thereof in the control section 30.

In FIG. 2, the opening/closing control section of the electric expansion valve 3 is the first
As in the case of Fig. 0, the opening degree is used to determine whether the opening degree of the electric expansion valve 3 is almost open or close based on the discharge refrigerant temperature and suction refrigerant temperature of the compressor 1 detected by the temperature detector 6a56b. a determination means 13; a correction opening determination means 14 for determining a correction value for the current opening of the electric expansion valve 3 based on the determination result of the determination means 13; It has an opening degree control means 15 for controlling the opening degree of No. 3.

Further, the abnormality determination section of the electric expansion valve 3 includes a temperature detector 6C.
a time setting means 35 for inputting and controlling temperature information of the indoor heat exchanger 4 (see FIG. 9) detected by the compressor at the time of starting the compressor and after a certain period of time has elapsed; It has an abnormality determining means 36 that determines whether the electric expansion valve is abnormal based on each temperature information, and an operation stopping means 37 that stops the operation of the compressor when the determining means 36 determines that there is an abnormality.

Next, the present embodiment configured as described above and its operation will be explained according to flowchart 1 shown in FIG.

First, before explaining the operation, FIG. 4 will be explained.

FIGS. 4(A) and 4(B) show the indoor heat exchanger 4 during normal control during heating and cooling and when the electric expansion valve 3 is fully closed.
It shows the temperature change of the outdoor heat exchanger 5 (see FIG. 9 for both).

Normally, when the compressor is stopped, the temperature of the heat exchangers 4 and 5 is the same as the temperature indoors and outdoors, and when the compressor is started, the temperature of the indoor heat exchanger 4 during heating is as shown in Figure 4 (A ), and the temperature of the outdoor heat exchanger 5 increases as shown in Fig. 4 (B
) decreases as shown by the solid line. Furthermore, when the electric expansion valve 3 is fully closed, the refrigerant will no longer flow to the heat exchanger, so after a certain period of time from the time the compressor is started, the temperature of the indoor and outdoor heat exchangers 4.5 will decrease. Figure 4 (A,), (B)
As shown by the broken line, it is almost the same as when the compressor is stopped.

In addition, during normal control during cooling, the indoor heat exchanger 4
And the temperature of the outdoor heat exchanger 5 is shown in FIG. 4(C).

The temperature of the heat exchanger 4.5 changes as shown by the solid line in (D), and the temperature of the heat exchanger 4.5 when the electric expansion valve 3 is fully closed is shown in (C).

The temperature characteristics are shown by the broken line in (D).

Therefore, by detecting the difference between the heat exchanger temperature at the time of starting the compressor and the heat exchange temperature after a certain period of time, it is determined whether the electric expansion valve 3 is fixed in a fully closed state. be able to.

When the control program shown in FIG. 3 starts with the start of operation of the control section 30, first, in step 40, it is determined whether the compressor has started. If it is determined that the compressor has been started, the process proceeds to step 41 and a timer is started. Then, in the next step 42, the temperature T h a x of the indoor heat exchanger 4 at the time of starting the compressor is taken in. In the next step 43, it is determined whether the count TI of the timer has reached a predetermined value or more. That is, it is determined whether a certain period of time, for example, 5 minutes has passed since the compressor was started, and when it is determined that 5 minutes have passed, the process moves to step 44 and the temperature of the indoor heat exchanger 4 after 5 minutes has elapsed. T'llX
Incorporate.

In step 45, the operation mode of the air conditioner is determined,
If it is determined that the heating operation is being performed, the process proceeds to step 46, and if it is determined that the cooling operation is being performed, the process proceeds to step 47.

In step 46, when it is determined that the T'kaxT h e xO difference is less than a certain value, for example, less than 4 degrees, it is determined that there is an abnormality in the electric expansion valve 3, that is, the expansion valve 3 is fully closed and in a fixed state. It is determined that the abnormal stop command is output to the drive circuit 12 and the compressor operation stop means 3 is activated.
7 to bring the compressor motor 1a to an emergency stop. Also, in step 46, T'hax Thaw > 4.
When it is determined that the electric expansion valve 3 is normal, the process proceeds to step 49 and normal operation control is executed.

On the other hand, in step 47, T'h*x
Th. When it is determined that the difference between
It is determined that the compressor remains fully closed and fixed, and the process proceeds to step 48, where the compressor is brought to an emergency stop. Further, if the determination result in step 47 is T'heX'rh@X <4deg, the process moves to step 49 and normal operation is performed.

As described above, in this embodiment, in the case of an abnormal state in which the electric expansion valve 3 fails and does not operate with the opening fully closed, this is set to the temperature 1 ham of the indoor heat exchanger 4 at the time of starting the compressor, which is a constant value. Since the operation of the compressor is stopped by detecting the difference in the temperature T'h*x of the indoor heat exchanger 4 after the elapse of time, overheating and burnout of the compressor motor can be prevented.

Note that the normal opening/closing control operation of the electrically operated expansion valve 3 in FIG. 2 is the same as that in FIG. 11, so a description thereof will be omitted.

5 and 6 show a second embodiment of the air conditioner of the present invention, FIG. 5 is a functional block diagram of the opening/closing control section and abnormality determination section of the electric expansion valve, and FIG. It is a flowchart showing the operating procedure.

In FIG. 5, the same reference numerals as in FIG. 2 represent the same parts, and the difference from FIG. The temperature information from the temperature detection 6d of the outdoor heat exchanger 5 is input to the electric expansion valve abnormality determining means 38.

Next, the determination control of an abnormal state in which the electric expansion valve 3 is fixed in a fully closed state will be explained according to the procedure of the control program shown in FIG.

When the control program shown in FIG. 6 starts with the start of operation of the control section 30, first, in step 50, it is determined whether the compressor has been started. When it is determined that the compressor has been started, the process proceeds to step 51 and a timer is started. In the next step 52, the temperature T h m w of the indoor heat exchanger 5 at the time of starting the compressor is taken. Then, in the next step 53, it is determined whether the count content TI of the timer has reached a predetermined value or more. That is, it is determined whether a certain period of time, for example, 5 minutes has passed since the compressor was started, and
If it is determined that 5 minutes have elapsed, the process moves to step 54 and the temperature T゛hQx of the indoor heat exchanger 5 after 5 minutes has passed is taken in.

In step 55, the operation mode of the air conditioner is determined,
If it is determined that the heating operation is being performed, the process proceeds to step 56, and if it is determined that the cooling operation is being performed, the process proceeds to step 57.

In step 56, when it is determined that the difference between T'hexTh e It is determined that there is an error, and the process proceeds to step 58, where an abnormal stop command is output to the drive circuit 12 and the compressor operation stop means 3
7 to bring the compressor motor 1a to an emergency stop. Also, in step 56, T'hax Thaw > 4d
If it is determined that the electric expansion valve 3 is normal, the process proceeds to step 59 and normal operation control is executed.

On the other hand, in step 57, T″ha, l″r’bo
When it is determined that the difference in x is not less than a certain value, for example -4 degrees or less, it is determined that there is an abnormality in the electric expansion valve 3, that is, the expansion valve 3 is in a fully closed and fixed state, and the process proceeds to step 58. Bring the compressor to an emergency stop. Also, the determination result in step 57 is T' +i+x T htiX<-4d
If it is eg, the process moves to step 59 and normal control operation is executed.

In the second embodiment as described above, the same effects as in the first embodiment can be obtained.

7 and 8 show a third embodiment of the air conditioner of the present invention, FIG. 7 is a functional block diagram of the opening/closing control section and abnormality determination section of the electric expansion valve, and FIG. It is a flowchart showing the procedure of the operation.

In Fig. 7, the same symbols as in Fig. 2 represent the same parts, and the difference from Fig. 2 is the indoor heat exchanger temperature detection 6C.
In addition to the time setting means 35, an indoor temperature detector 38 is provided, and abnormality of the electric expansion valve 3 is determined based on the indoor heat exchanger temperature and the room temperature after a certain period of time by the time setting means 35. It is.

Next, a means for determining an abnormal state in which the electric expansion valve 3 is fixed in a fully closed state will be explained according to a control program shown in FIG.

When the control program shown in FIG. 8 starts with the start of operation of the control section 30, first, in step 60, it is determined whether the compressor has been started. When it is determined that the compressor has been started, the process advances to step 61 and a timer is started. In the next step 62, it is determined whether the count TI of the timer has reached a predetermined value or more. That is, it is determined whether a certain period of time, for example, 5 minutes has passed since the compressor was started, and when it is determined that 5 minutes have passed, the process moves to step 63 and the temperature information of the indoor heat exchanger 4 and the indoor temperature are determined. The information is taken in, the calculation of ΔT - indoor heat exchanger temperature - indoor temperature is executed, and the temperature difference ΔT between the two is below a certain value, for example 4.
When it is determined that the temperature is below deg, the electric expansion valve 3
It is determined that the compressor is fully closed and fixed, and the process proceeds to step 65, where the compressor is brought to an emergency stop.

If it is determined in step 63 that 1ΔTi<4deg, it is determined that the electric expansion valve 3 is normal, and the process proceeds to step 66, where normal operation control is performed.

This third embodiment also provides the same effects as the first embodiment.

〔Effect of the invention〕

As described above, according to the present invention, when the electric expansion valve is fixed in a fully closed state, this is detected as an abnormality and the operation of the air conditioner is stopped. The compressor is not driven while being fixed in the closed state, which prevents overheating and burnout of the compressor motor, and has the effect of improving the reliability of the entire system as an air conditioner.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a first embodiment of the control system for an air conditioner according to the present invention, Fig. 2 is a functional block diagram for controlling the electric expansion valve in Fig. 1, and Fig. 3 is a functional block diagram thereof. Flowchart showing the operating procedure, Fig. 4 (A), (
B) shows the temperature change of the heat exchanger to explain its operation.
The figure is a functional block diagram showing a second embodiment of the control section of the electric expansion valve according to the present invention, FIG. 6 is a flowchart showing its operating procedure, and FIG. A functional block diagram showing the third embodiment, FIG. 8 is a flowchart showing its operating procedure, FIG. 9 is a configuration diagram of a basic refrigeration cycle of an air conditioner, and FIG. 10 is an electrical block diagram of a conventional control unit. , FIG. 11 is a functional block diagram for controlling a conventional electric expansion valve, and FIG.
The figure is a flowchart showing the operating procedure. DESCRIPTION OF SYMBOLS 1... Compressor, 1a... Compressor motor, 2... Four-way valve 3... Electric expansion valve, 4.5... Heat exchanger, 1
DESCRIPTION OF SYMBOLS 1...Temperature detection unit, 13...Electric expansion valve opening determination means, 14...Electric expansion valve correction opening determination means, 15
. . . Electric expansion valve opening control means, 30 . . . Control unit,
35... Time setting means, 36... Electric expansion valve abnormality determination means, 37... Compressor operation stop means, 38...
Indoor temperature detector. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent: Masuo Oiwa (2 people) Figure 3 Figure 4〈□〉〈When cooling〉 Compression I! ION detection Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 1Q Fig. 6.

Claims (1)

[Claims] (1) In an air conditioner that configures a refrigeration cycle by connecting a compressor, a four-way valve, an indoor/outdoor heat exchanger, and an electric expansion valve in a closed loop, temperature information from the means for detecting the operating state of the refrigeration cycle is used. The control unit includes a control unit that controls starting and stopping of the compressor and opening and closing of the electric expansion valve based on the compressor, and the control unit counts the time from the start of the compressor,
means for determining an abnormality in the electric expansion valve based on the temperature of the heat exchanger after starting the compressor and the time set by the time setting means or the indoor temperature after the set time; An air conditioner characterized by comprising means for stopping operation of the compressor when the abnormality determining means determines that the expansion valve is abnormal.